Challenge Thread: The fastest breadboard oscillator on the mudball

[0culus]

I got it alive by replicating the circuits I've been playing with already (colpitts), but it's not much faster than what I was doing before (reached 693 MHz). I need to really tweak the inductor, or better yet, find a way to eliminate it and use the parasitics.

[SilverSolder]

What's the benefit/purpose of the copper mesh "cage" around the oscillator?  Wouldn't that just create extra capacitance and lower the frequency?  (RF n00b asks)

[0culus]

Rules clarification: if I manage to get the (erstwhile) second harmonic larger than the (erstwhile) fundamental, can I claim success under the clause "distorting and leeching harmonics"? If so, I finally got something out of the 2SC5227. It's rather unstable and the waveform isn't pretty.

[joeqsmith]

What's the benefit/purpose of the copper mesh "cage" around the oscillator?  Wouldn't that just create extra capacitance and lower the frequency?  (RF n00b asks)

If you watched that early video, I had the Signal Hound monitoring the peak while waving my hand a couple of feet away from it.   The shield helps reduce the sensitivity to changes in the parasitics. 

The problem with this particular oscillator is not making it go faster but how to tell how fast it's going.      

[SilverSolder]

What's the benefit/purpose of the copper mesh "cage" around the oscillator?  Wouldn't that just create extra capacitance and lower the frequency?  (RF n00b asks)

If you watched that early video, I had the Signal Hound monitoring the peak while waving my hand a couple of feet away from it.   The shield helps reduce the sensitivity to changes in the parasitics. 

The problem with this particular oscillator is not making it go faster but how to tell how fast it's going.      

 

Is it possible to beat against another oscillator nearby and pick the difference signal up with the instruments that have run out of breath?

[ogden]

Rules clarification: if I manage to get the (erstwhile) second harmonic larger than the (erstwhile) fundamental, can I claim success under the clause "distorting and leeching harmonics"? If so, I finally got something out of the 2SC5227. It's rather unstable and the waveform isn't pretty.

We (again) are approaching dangerous rule bending territory. Planning to use U9391C or alike in this contest? First you would want to demonstrate spectrogram that includes everything - from DC up-to harmonic of interest so we can see that fundamental indeed is heavily supressed. I would say that if your frequency counter shows harmonic freq instead of fundamental, then it is fair entry.

[0culus]

Dude, will you chill out with all the "dangerous rule bending" crap? This is for fun, no one is playing for money here. Why would I blatantly cheat by using an IC, anyway.  If I was going to do that I could just hook up a microwave sig gen and blow away everyone.  I'm experimenting with different inductor configurations and I happened upon one that made the second harmonic take over by a few dB. All I want is clarification from the OP about how many dB down the the old fundamental ought to be in this situation...

[BreakingOhmsLaw]

Rules clarification: if I manage to get the (erstwhile) second harmonic larger than the (erstwhile) fundamental, can I claim success under the clause "distorting and leeching harmonics"? If so, I finally got something out of the 2SC5227. It's rather unstable and the waveform isn't pretty.

As ogden pointed out, the counter will need to count the harmonic. You will probably need more than 3dB suppression of the fundamental for that to happen.
Bear in mind, with 1.5pF breadboard parasitics, you would need single digit resistance for a 10GHz RC high pass filter.
But i am ready to be proven wrong by voodoo engineering any time! :-D

[BreakingOhmsLaw]

Added a scope shot to make it official.

Is that the new LeCardboyrd scope? Niiiiiice! Looking forward to a full review in TEA.

[ogden]

Dude, will you chill out with all the "dangerous rule bending" crap? This is for fun, no one is playing for money here.

Whatever Dude cool down yourself. I am stirring the pot, for entertainment purposes. Please don't call it Breadboard Oscillator especially when winning entries do not follow rule #3, part "All electrical connections between individual parts must be made by the breadboard contacts".

Why would I blatantly cheat by using an IC, anyway. 

Usually main part of Comb Generator is just diode. Thou needs powerful signal. Anyway I was kidding. Noticed smiley that looks like: ? It means: "laugh". Comprehend?

I'm experimenting with different inductor configurations and I happened upon one that made the second harmonic take over by a few dB.

Good! As I said - would be nice to show fundamental together with harmonic, preferably using two markers, if any.

[0culus]

Rules clarification: if I manage to get the (erstwhile) second harmonic larger than the (erstwhile) fundamental, can I claim success under the clause "distorting and leeching harmonics"? If so, I finally got something out of the 2SC5227. It's rather unstable and the waveform isn't pretty.

As ogden pointed out, the counter will need to count the harmonic. You will probably need more than 3dB suppression of the fundamental for that to happen.
Bear in mind, with 1.5pF breadboard parasitics, you would need single digit resistance for a 10GHz RC high pass filter.
But i am ready to be proven wrong by voodoo engineering any time! :-D

Fair enough. My sleep deprived brain came up with this monstrosity.  The fundamental and second harmonic are essentially equal, but sadly the second harmonic is already getting pretty far outside the 7104 (and FET probe's) passband so I can't see what it looks like in time domain with my current tools. Basically, it's the same Colpitts oscillator except with the 2SC5227 transistor (which had already been helpfully mounted in a tiny PCB with legs for breadboarding) and this train of inductors that aren't directly in the circuit but are modifying the parasitics.

[0culus]

Dude, will you chill out with all the "dangerous rule bending" crap? This is for fun, no one is playing for money here.

Whatever Dude cool down yourself. I am stirring the pot, for entertainment purposes. Please don't call it Breadboard Oscillator especially when winning entries do not follow rule #3, part "All electrical connections between individual parts must be made by the breadboard contacts".

Why would I blatantly cheat by using an IC, anyway. 

Usually main part of Comb Generator is just diode. Thou needs powerful signal. Anyway I was kidding. Noticed smiley that looks like: ? It means: "laugh". Comprehend?

I'm experimenting with different inductor configurations and I happened upon one that made the second harmonic take over by a few dB.

Good! As I said - would be nice to show fundamental together with harmonic, preferably using two markers, if any.

If you're stirring the pot, it may be coming across as more combative than you are intending it to.  I don't know if it's the language barrier, but since you had to explain it you might want to be more careful.

Anyway, let's see your efforts. Otherwise you're just the peanut gallery. 

[0culus]

I'm going to order some much faster parts from digikey this weekend anyway. I'm not going to bother trying to desolder these.

[0culus]

If you're stirring the pot, it may be coming across as more combative than you are intending it to.

Usually people become hyperventilated about my sentences ending with smileys Who is combative here? BTW I did not resort to personal insults like you with your "language barrier", "peanut gallery", not even mentioning personal insults directed at me from contest leader.

Snip

LOL.

> claims to be kidding because emoticons
> wants to have it both ways and be insulted by mine

I’m not the first person to call you out on how you’re acting in this thread. If you can’t handle being called out and having it dished back at you, that’s not my problem and I have little sympathy. No one asked you to be the self appointed breadboard oscillator rules cop. The OP is doing a fine job of arbitration so please leave it to him.

[BreakingOhmsLaw]

Keep me out of this, and perhaps you should make an entry yourself for the others to scrutinize.

[BreakingOhmsLaw]

Question to OP: If I do not show my entry due to lack of MW counter/SA, I can't post here in this thread?

Highly encouraged to post it anyway. This competition is for fun and educational purposes.
And to disprove the false legend that "breadboards can't go over 10MHz".
I don't have access to anything over 1GHz myself, so I will be contributing some related stuff now and then like i did yesterday.
Cheers.

[trash]

Wow, Bitchin !
I've been away for a week and Joe is up at 16Ghz and the 2GHz version is still sitting on my work bench.
I like the shield, I hadn't thought of doing that.

I've got some new ideas I want to try with a completely different circuit tonight.
I'm back at work again for another week so I only have tonight for some development.

It looks like there is a lot more interest in the competition now and people have realised how easy it is to break the 1GHz barrier even on a breadboard.

[trash]

I don't have access to anything over 1GHz myself, so I will be contributing some related stuff now and then like i did yesterday.

I would not stress about not having any gear over 1GHz. It's just as easy to test your oscillators and do it REALLY cheap.

The first thing you probably already have. A USB TV dongle.  Run some SDR software and you have a spectrum analyser that is good up to almost 2GHz.  For only $20 !

The next thing to do is get your hands on some downconverters. Again, you probably already have these things.

The first is a satellite TV receiver. They're good to 2GHz. The IF stages also make good spectrum analysers on their own.
Those old MMDS antennas. The downconverters on them have a local oscillator of 1950MHz. They will give you access up to 3GHz, especially if you remove any front end filtering.

Next is a C Band satellite LNC. They're good for 3GHz to 4.5GHz. Again, if you have an older on you don't mind removing the front end filtering, you can push them out to 5GHz. 

Next is 10GHz. If you have an old automatic door motion detector, a radar detector, or a burgular alarm microwave motion detector.
That will give you access to ~9-11GHz.

Ku Band LNC's, they're give you access to 9-13GHz and you can modify them well out to 15GHz. I've got an old Plessey 2.2dB NF LNC that I pushed out past 15GHz. (trying to get to 24GHz).

K Band Radar detector will give you 24GHz and some of the images. 24GHz gunn modules, you can mix them down and run them on your CRO or SDR.

And even then, you can still go dumb as a box of hammers simple diode wavemeter.
Two wires in parallel with a diode on the end connected to your CRO with a slow sweep looking for tiny changes in DC.
Connect the signal source to the diode and short the two wires. Move the short up and down the wires and look for nulls and peaks.
Measure the intervals which will be half wavelength.   That's what we used to do in the days before rectum paralysers became dirt cheap.

[trash]

Looks like I've reached the end of the line tonight.
Doubling the output of the 2GHz oscillator to give 4GHz should have been a walk in the park. But I was getting nothing.
I couldn't work out what was going on. So I fired up the sig gen and nothing out of the doubler either.  So I thought the doubler was broken and I rebuilt it. And still nothing.  Eventually I went and got a C band signal source and nothing on the spec-an either.
 Ah shit... looks like the >2GHz section in my spectrum analyser has stopped work so I've been stuck at 2GHz not realising that the comb generator I built was probably cranking out harmonics at 10GHz last week. Doh !

So I had to change to take some of my own advice and fire up the X band mixer to see if anything was happening at 10GHz.
Sure enough there was a carrier there. So tonight I thought I'd go back to the simplest circuit and see if I could make it work.
A negative resistance diode (Tunnel diode) set up on a skeleton waveguide and woohoo ... the dirtiest signal I've seen at 10.7GHz.
It's completely useless as any kind of oscillator it's that bad. But it is enough to claw back some of my dignity for now.
So it looks like I'm out for the time being. I'm going to have to now find some time to repair the spec-an.

[mnementh]

Taking the new oscillator for a test drive and blowing the old record out of the water and it's only in first gear idling...      Added a scope shot to make it official.   

What an adorable little Faraday cage! Just the right size for a Lego guy and his cellphone!     No, seriously... righteous sqwawk, man. 

Dude, will you chill out with all the "dangerous rule bending" crap? This is for fun, no one is playing for money here.

Whatever Dude cool down yourself. I am stirring the pot, for entertainment purposes. Please don't call it Breadboard Oscillator especially when winning entries do not follow rule #3, part "All electrical connections between individual parts must be made by the breadboard contacts".

If you're stirring the pot, it may be coming across as more combative than you are intending it to.  I don't know if it's the language barrier, but since you had to explain it you might want to be more careful.

Anyway, let's see your efforts. Otherwise you're just the peanut gallery. 

*tosses peanuts at Oculus and shells at ogden*

Go sine wave! rah, rah, rah! 

mnem
*Impairing SNR since nineteen-mumblety-mumble*   

[0culus]

Keep me out of this, and perhaps you should make an entry yourself for the others to scrutinize.

I did? I even posted photos and spec an screen grabs. ogden is right, of course. That stupid pcb the transistor is mounted on is probably causing all sorts of havoc, but I see little point in trying to desolder such a tiny part when I am already planning on ordering some new parts which will come on a tape.  I reached a new personal record, and to be fair since the fundamental and the second harmonic are all but equal, I'm only claiming the fundamental here.  I was able to get a counter to grab the second harmonic but it wasn't stable so, I'm going to make a judgement call and say that it doesn't count...see what I did there? 

Rules clarification: if I manage to get the (erstwhile) second harmonic larger than the (erstwhile) fundamental, can I claim success under the clause "distorting and leeching harmonics"? If so, I finally got something out of the 2SC5227. It's rather unstable and the waveform isn't pretty.

As ogden pointed out, the counter will need to count the harmonic. You will probably need more than 3dB suppression of the fundamental for that to happen.
Bear in mind, with 1.5pF breadboard parasitics, you would need single digit resistance for a 10GHz RC high pass filter.
But i am ready to be proven wrong by voodoo engineering any time! :-D

Fair enough. My sleep deprived brain came up with this monstrosity.  The fundamental and second harmonic are essentially equal, but sadly the second harmonic is already getting pretty far outside the 7104 (and FET probe's) passband so I can't see what it looks like in time domain with my current tools. Basically, it's the same Colpitts oscillator except with the 2SC5227 transistor (which had already been helpfully mounted in a tiny PCB with legs for breadboarding) and this train of inductors that aren't directly in the circuit but are modifying the parasitics.

[joeqsmith]

Is it possible to beat against another oscillator nearby and pick the difference signal up with the instruments that have run out of breath?

Yes.  This was also covered in those early videos and some of my posts.  Trash was also confused by it.  Maybe this post will help you:
https://www.eevblog.com/forum/projects/challenge-thread-the-fastest-breadboard-oscillator-on-the-mudball/msg3095837/#msg3095837

As I mentioned in that post, the oscillator is only good to 8GHzish and the mixer had a max IF of 4GHz, so  8+4=12GHz was about it.  The next limit was the DSO which has an analog BW of 5GHz but my Signal Hound is good for 6GHz.   In the following post I show the Signal Hound looking at the previous record holder.   You can see the signal is there but it's suppressed.
 
https://www.eevblog.com/forum/projects/challenge-thread-the-fastest-breadboard-oscillator-on-the-mudball/msg3097054/#msg3097054

There has been a fair amount of information posted if you care to dig into it.    Better yet, build something!  Be the second member of the 5GHz club!!

[PA0PBZ]

@joeqsmith, can you post a picture of your setup that shows all the details (like I did)? I've seen the video's (too far away or too fast panning) and I've seen the pictures of some details but I think I've not seen the whole picture? Correct me if I'm wrong and then point me to what I missed please.

[SilverSolder]

Is it possible to beat against another oscillator nearby and pick the difference signal up with the instruments that have run out of breath?

Yes.  This was also covered in those early videos and some of my posts.  Trash was also confused by it.  Maybe this post will help you:
https://www.eevblog.com/forum/projects/challenge-thread-the-fastest-breadboard-oscillator-on-the-mudball/msg3095837/#msg3095837

As I mentioned in that post, the oscillator is only good to 8GHzish and the mixer had a max IF of 4GHz, so  8+4=12GHz was about it.  The next limit was the DSO which has an analog BW of 5GHz but my Signal Hound is good for 6GHz.   In the following post I show the Signal Hound looking at the previous record holder.   You can see the signal is there but it's suppressed.
 
https://www.eevblog.com/forum/projects/challenge-thread-the-fastest-breadboard-oscillator-on-the-mudball/msg3097054/#msg3097054

There has been a fair amount of information posted if you care to dig into it.    Better yet, build something!  Be the second member of the 5GHz club!!

I watched the video and I am beginning to see what you are doing.

I'm still trying to understand the limitations at DC and 400Hz so 5GHz is a bit down the road! 

[joeqsmith]

@joeqsmith, can you post a picture of your setup that shows all the details (like I did)? I've seen the video's (too far away or too fast panning) and I've seen the pictures of some details but I think I've not seen the whole picture? Correct me if I'm wrong and then point me to what I missed please.

No problem.  There's 6 pages of history now.  I'm guessing its becoming too much to follow.  These are what I consider my key posts from the earliest to the most current.   

Asking for clear definition:
https://www.eevblog.com/forum/projects/challenge-thread-the-fastest-breadboard-oscillator-on-the-mudball/msg3083554/#msg3083554

Showing the early concept:
https://www.eevblog.com/forum/projects/challenge-thread-the-fastest-breadboard-oscillator-on-the-mudball/msg3084016/#msg3084016

Showing the first attempts to couple to the coax using the same section of wire:
https://www.eevblog.com/forum/projects/challenge-thread-the-fastest-breadboard-oscillator-on-the-mudball/msg3084601/#msg3084601

Showing wiring of the previous oscillator, which is basically the same for the new one:
https://www.eevblog.com/forum/projects/challenge-thread-the-fastest-breadboard-oscillator-on-the-mudball/msg3097054/#msg3097054

Showing build up of the current oscillator with Kapton:
https://www.eevblog.com/forum/projects/challenge-thread-the-fastest-breadboard-oscillator-on-the-mudball/msg3098642/#msg3098642

Showing construction of the shield:
https://www.eevblog.com/forum/projects/challenge-thread-the-fastest-breadboard-oscillator-on-the-mudball/msg3100257/#msg3100257

I have not shown the addition of the LED to the battery pack.